碱法苇浆中己烯糖醛酸及其它碳水化合物发色基团的研究

HexA and Other Carbohydrate Chromophores in Unbleached Reed Alkaline Pulp

用甲酸钠选择性水解结合紫外分光光度法 ,研究了碱法苇浆中己烯糖醛酸 (HexA)及其它几种碳水化合物发色基因 ,用原子吸收光谱法测定未漂浆中金属离子的分布。结果表明 ,未漂碱法苇浆中存在着多种与碳水化合物有关的发色基团 ;HexA含量甚低 ,其含量高低对Fe、Mn等过渡金属离子没有对应关系 ;各种碳水化合物发色基团对酸预处理及氧气漂白的稳定性均较差。

By means of selective hydrolysis with sodium formate solution and UV spectrometer, hexenuronic acid groups(HexA) and other chromophoric groups come from carbohydrates in unbleached reed soda green oxygen pulp(i.e. alkaline pulp) are studied. Metal ions in the pulp are determined with atomic absorption spectrometer. The results show that, in addition to HexA, there are some chromophores originated in carbohydrates. The HexA content for alkaline reed pulp is much lower than that in kraft wood pulp. The ions of Fe, Mn, etc in reed pulp are not related to the content of HexA in reed pulp. Pretreatment with hot diluent acid can significantly degrade all chromophores mentioned above, resulting in a obvious improvement on oxygen bleaching efficiency of reed pulp. The HexA and other chromophoric groups are remarkably degraded during conventional oxygen bleaching.